Near-infrared enhanced position-sensitive avalanche photodiodes

A laser processing method was used to microstructure the surface of position-sensitive silicon avalanche photodiodes (PSAPDs) and enhance their near-infrared response. Following laser microstructuring and high-temperature annealing, experiments were performed on PSAPDs to determine their performance at 1064 nm. As a result of this processing method, we fabricated APDs with quantum efficiencies as high as 58% at 1064 nm. The enhanced near-infrared response has now been realized in both lateral effect and quadrant-type PSAPDs without altering their electronic noise, avalanche gain or position resolution. A near-infrared-enhanced PSAPD module with temperature control and position output was assembled and tested.